Rules
Athletes with february birthdays: what to know and why
Athletes with February birthdays: what a record claim needs on both sides of the subtraction, why the birth side is soft, and how recognition really works.
Section
Rules
Rules
July birthdays: research methods and useful context
July birthdays: day-of-year arithmetic, how the weekday walks from year to year, why age is a definition rather than a subtraction, and why none is shown.